Punch.



E. D. GILBERT.

PUNCH.

APPLICATION FILED FEB. 12. 1916.

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THE COLUM PLANonRAPl-l c0, WASHINGTON, D. c.

EDMUND I). GILBERT, OF PHILADELPHIA, PENNSYLVANIA.

PUNCH.

Specification of Letters Patent.

Patented May 2, 1916.

Application filed February 12, 1916. Serial No. 77,838.

To all whom it may concern Be it known that I, EDMUND D. GILBERT, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Punches, of which the following is a specification.

My invention relates to improvements in a punch and particularly relates to a hand punch used in dentistry, which is adapted for punching holes in sheet rubber, known as a rubber-dam, and which requires a small hole formed therein, so that the rubber-dam may be placed over a tooth with the latter projecting through the hole, for the purpose of keeping moisture away from the tooth.

The object of my invention is to con struct a punch in which the movement of the cutting-punch is in a straight line and acts in direct alinement with the die.

A further object of my invention is to construct the punch so that it may be conveniently gripped in the hand when in operation; and a still further object of my invention is to provide a novel mechanism for mounting the die in the frame.

In the accompanying drawings: Figure 1, is a side elevation of my improved punch; Fig. 2, is a vertical section on line 22 Fig. 1; Fig. 3, is a horizontal section on line 33 Fig. 1; Fig. 1, is a horizontal section on line 44: Fig. 1; and Fig. 5, is a vertical section on line 5-5 Fig. 3.

Referring to the drawings in which like references refer to like parts; 1 represents the frame in which is slidably mounted the rod 2, having a conical cutting punch 3 formed upon its lower end. The frame 1 is provided with a bearing member 4, in which the rod 2 is slidably mounted. The bearing member 1 is formed at right-angles with the upper bar 5 of the frame which projects in either direction from the bearing member 4,'to form a finger grip bar around which the fingers may be conveniently hooked and pressure exerted by the palm of the hand upon the handle 6 secured on the outer end of the rod 2. The frame 1 also consists of a lower arm 8, upon which is mounted the die plate 10. The upper and lower members of the frame 1 are connected by a curved portion which forms part of the frame, as shown in Fig. 1; thus a frame is formed in one piece and the curved portion is made sufficiently strong and rigid to resist any pressure that could be exerted by the hand.

A coiled spring 12 embraces the rod 2 and tends to hold the rod and the cutting punch away from the die plate 10. A stop in the form of a set-screw 13, is provided in the bearing member 1, which engages a shoulder 14, formed on the rod 2 and prevents the spring from forcing the rod out of the bearing member a.

The die plate 10 is rotatably mounted upon the lower arm 8 of the frame 1, so that apertures 15 of diiferent sizes may be brought into alinement with the cutting punch 3, for cutting holes of different sizes in the rubber-dam. The die-plate 10 is mounted upon a screw 18, which is free to rotate in an aperture 19, formed in the arm 8. The screw 18 is inserted into the threaded aperture formed in the center of the die plate 10, so that the shoulder 20 formed on the screw 18, tightly impinges against the dieplate which secures the screw and the die-plate together. The aperture formed in the arm 8 for the screw 18, has an enlarged portion into which the head of the screw enters. A coiled spring 22 embraces the screw 18 and is compressed between the head of the screw and the shoulder 25 in the arm 8, and firmly holds the die plate 10 upon the arm 8.

A stop 26 is provided upon the arm 8 to hold the disk 10 from rotating. Said stop 26 projects above the upper surface of the arm 8, and the die plate 10 is reamed out upon the under side thereof so that each of the cutting apertures 15 formed in the disk will be enlarged and fit over the projecting stop 26. The stop 26 upon the arm 8, is located in alinement with the cutting punch 3 and the die plate 10 may be rotated so as to bring any one of the different sized cutting apertures 15, of the die plate, into alinement with the cutting punch by lifting the die plate, against the action of the spring 22, and then rotating the die plate until the desired aperture fits over the stop 26.

The stop 26 is preferably made in the form of a conical bushing with an opening 27 formed through the same to discharge the cuttings through the same. The stop 26 may be made in a solid piece if desired as the cuttings may be discharged from the apertures 15 of the die plate by rotating the die plate until the particular aperture is at one side of the arm 8, as shown in Fig. 3.

By placing the stop 26 in alinement with the cutting punch 3, any number of cutting apertures may be formed in the die plate 10, and located at any convenient distance apart without accurately spacing them at any particular radial points.

By constructing the punch in the above described manner the cost of manufacture is greatly reduced; the cutting elficiency is increased due to the direct action of the cutting punch upon the die plate; the die plate may be readily rotated and it will always center the aperture in alinement with the cutting punch, and the finger grip bar forms a convenient construction for holding the punch in one hand.

Having thus described my invention I claim and desire to secure by Letters Patent:

1. In a punch the combination of a frame, a cutting punch, a bearing member forming part of said frame in which said cutting punch is slidably mounted, a finger grip formed upon the frame at either side of the said bearing member, and a die plate mounted upon the frame.

2. In a punch the combination of a die plate, a bearing member in which said die plate is rotatably mounted, a,lug forming a stop adapted to hold the die plate in a fixed position upon said bearing member, a

spring to hold the die plate upon the bearing member and permit the die plate to be disengaged from the said stop and rotated, and a cutting tool mounted upon a second bearing member acting in conjunction with the die plate.

3. In a'punchthe combination of a frame, a cutting punehmounted in the frame, a die plate having cutting apertures formed therein, a screw rotatably mounted in an aperture formed in the frame, said screw secured to said die plate, a spring upon the screw tending to hold the die plate upon the frame and a stop formed upon the frame to engage said die plate. 7

4c. In a punch the combination of a frame, a cutting punch mounted in the frame, a die plate having cutting apertures formed therein, a screw rotatably mounted in the frame and carrying the die plate, a spring" upon the screw tending to hold the die plate upon the frame, a stop located upon the frame in alinement with the cutting punch, said stop projecting into the aperture formed in the under side of the die plate and adapted to hold the die plate in alinement with the cutting punch.

In testimony whereof I have aiiixed my signature in the presence of two witnesses. EDMUND D. GILBERT. Witnesses MEYER Knaus, F. Rosn CHALMERs.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

